Climate change over the past decade has strongly impacted many facets of agriculture and remains to be one of our primary concerns.

We live milder winters, earlier bud breaks but at the same time, more episodes of violent and delayed spring frost. Frost spares no one today. This was evident during the frosts of April 2017 which affected the major parts of French vineyards as well as the other produce across Europe.

In this context, the fight against frost is one of the core foundations in sustaining our farms, even more than ever, considering the wide fluctuations in temperature.

Water spraying

The continuous sprinkling of water makes it possible to set up a water/ice balance around the bud for temperatures to not fall below 0ºC.

The sprinkling of water can be complicated: Even though water droplets freeze and create frost, they generate heat. The process of spraying if done incorrectly, can both reduce temperatures but at the same time increase frost, which would be damaging to your produce.

It is important to recognize that this method only prevents the temperature of the plant from falling below 0°C. It does not heat the temperature of the air nor the plant significantly.

Lighting STOPGEL GREEN Antifreeze candles makes it possible to keep temperatures above 0ÂºC by warming the layer of air in contact with the crops. STOPGEL GREEN candles stand out from braziers or big stoves that, due to a chimney effect, lose heat and apt cold air to crops and soils, thus cooling certain areas to be protected.

STOPGEL GREEN offers an efficient heating method by setting up 6-liters candles evenly spaced across the field. The size of the STOPGEL GREEN candles make it possible to stay within the zone of temperature inversion, thus allowing the circulation of heated air at the height of the trees, vines and/or crops. Depending on the number of STOPGEL GREEN candles used, the temperature can be kept above 0ºC even during freezing weather down to -7ºC.

Figure 1. Zone of temperature inversion during a spring frost episode

(source : Omafra)

Image 3. STOPGEL GREEN Antifrost Candles lit in an orchard

Air ventilation

The method of air ventilation relies on two observations. First of all, cold air is found at the level of crops due to its higher density than warm air. Also, temperature increases a few meters over the field before decreasing again. Air ventilation puts in action the principle of temperature inversion by replacing the layer of cold air that is in contact with the crop by the warmer layer above it.

There are several types of equipment for air ventilation: fixed or mobile antifrost towers, also called wind turbines or the use of helicopters. The equipment and installation are expensive but can raise the temperature by 1 to 4 degrees Celsius.

When using a wind tower, it is essential to install additional heaters in the vineyard or the orchard with large antifrost candles such as 80-liters STOPGEL GREEN barrels combined with a chimney.

Image 4. Barrel STOPGEL GREEN for wind towers

Image 5. Barrel STOPGEL GREEN for wind towers with a chimney

For more information, please contact us

Tel. 33 (0)4 75 84 61 11 • Email : stopgel@wanadoo.fr

Specialized in the protection of orchards and vineyards against spring frosts,
we have been manufacturing STOPGEL antifrost candles since 1995.